Irrigation systems and irrigation methods have been under constant development for thousands of years, efficient water management has many times been an overall goal when new systems and methods have been introduced. The introduction of diesel and electric motors has enabled many new concepts when it comes to irrigation (or watering) of planted surfaces and advancements in terms of reduction in manual labor and costs have been made. There is a constantly growing need for better irrigation systems and irrigation methods in order to maximize water use efficiency, i.e. supplying each plant with the amount of water it needs, no more and no less, and at the same time minimizing water losses, e.g. due to evaporation.
This is particularly important in areas which are subjected to severe drought periods, as a consequence these areas often have strict water rationing. Moreover, in consideration of recent developments around the world, i.e. rapidly increasing population, the overall economical growth, climate changes and so on, irrigation water (ground water, surface water, etc.) is becoming a less abundant resource which puts high demands on irrigation techniques to maximize efficiency as irrigation water may not be considered an “unlimited resource” like it was just half a century ago.
There are several types of irrigation techniques, such as e.g. furrow, flood, sprinkler, spray, subsurface, drip, etc. each with their own advantages and disadvantages. When it comes to maximizing water efficiency one can generally say that sub-surface irrigation systems are preferable over surface irrigation systems (e.g. sprinklers, level basins, etc.), they are however often more expensive to install and/or maintain.
Furthermore, it has been shown that plant roots tend to grow in the direction of the moisture gradient, thus if the moisture level is kept higher below the roots than at a surface level, the plants (or vegetation) will develop a deeper root system which will result in very stable and durable plants in contrast to plants which have developed a rather shallow root system due to surface irrigation.
It is known in the art to provide sub-surface irrigation system in which apertured tubes/pipes or tubes with drippers/emitters are utilized to distribute water at predetermined positions. Examples of such system can be found e.g. in U.S. Pat. No. 5,590,980 and US 2008/0098652.
However, systems like these are often very complicated and costly, and furthermore pose great challenges when trying to achieve a completely uniform spread of water across a large area. Moreover, they often require significant lengths of pipes or tubes which may be troublesome when it comes to maintenance and repairs.
There is therefore a need for an improved method and system for subsurface irrigation or watering of planted surfaces, which allows for good water use efficiency, easy maintenance and at the same time improves cost-efficiency.